Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3c55135951c05c9…

MALICIOUS

PDF

83.6 KB Created: 2021-09-22 17:00:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 737a109a0e74e0c897eed7d1df7c2bfe SHA-1: ffff152fd9affaffa949eb5624911eb2694b744f SHA-256: d3c55135951c05c98b92c228fcc1388b5f8df3ad6557d0678530f4d3e4b6658b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external links, many pointing to compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely used to facilitate the redirection to these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://japan-railpass.info/images/blog/file/2745629055.pdf
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/1de6d466acaad9f5ede6f52a03ac565e/litakamalixo.pdf
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb58febb2c---bijatanapuwagifut.pdf
    • https://www.wemservice.com/ckfinder/userfiles/files/kutut.pdf
    • http://xfswchem.com/upload/files/sutenakobebateselefas.pdf
    • http://hasicimosnov.cz/foto/Image/file/kuwofasewikikuzinab.pdf
    • https://capital-publishing.com/ckfinder/userfiles/files/wotiraxuxijifujid.pdf
    • http://remaining-mc.de/userfiles/file/32494548726.pdf
    • http://arabic.cz/ckfinder/userfiles/files/nepiputajizixu.pdf
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614864b5d5673---sexaniduzaritakek.pdf
    • https://mastirz.com/userfiles/files/86852527992.pdf
    • http://melvin.cz/data/8458547814.pdf
    • http://nasledie-sluck.by/var/upload/file/susib.pdf
    • https://mhreng.com/userfiles/file/39044424266.pdf
    • http://davidhammerstein.org/ckfinder/userfiles/files/zijudupuzupika.pdf
    • http://aroma-es.red/yamituki-n/uploads/files/16691611353.pdf
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/c5m0jao3pqfurvk3ppff875ehr/vokitasusege.pdf
    • https://kit-veron.my/ckfinder/userfiles/files/40455715076.pdf
    • http://cck-brno.cz/ckfinder/userfiles/files/jisuxelofito.pdf
    • http://wskinbody.com/data/boardData/files/47125360506.pdf
    • http://gayaarchi.com/userfiles/file/20210917173629.pdf
    • http://www.wcd.com.tw/ezadmin/ckfinder/userfiles/files/3891527152.pdf
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148a13967a90---karisus.pdf
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/28864746317.pdf
    • https://g4m3s-4p1-12s1.com/contents/files/57714190853.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=backup+android+to+pc+free
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e3b2.bin
9e73c91824446470fd8b6b9972dbf1375becd6027d115a24698e9cb188909d20
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B2 10644 bytes
font_01_sfnt_off0000fc42.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC42 16792 bytes
font_02_sfnt_off00011454.bin
742ea887654c0d238ff866ca1559728254af523e4859c9a6ffbdea405e505f25
pdf-font-stream PDF embedded font (sfnt) at offset 0x11454 17396 bytes